12.7" GB Range Report

[dpete]

Don't want to take away from OP's post, but I shot mine and had some pretty nasty scratches on the case. Almost looked like it was scored with 100 grit sandpaper. Should I try polishing the chamber? First time I've ever encountered this problem.

The scratches in mine are visibly shallower after the polishing sessions I have done with lapping compound and a .45 cal bore mop. Another member here had a similar issue with a different barrel and his description of his fix is here:
http://www.65grendel.com/forum/showt...cratched/page2 post #32

I may try this to finish the job. Much less clean up than getting left over lapping compound flushed out of the chamber and barrel.

[Schrambo]

Well crap, I pulled the cases from the 12.7" brass catcher, and it looks like I've a got a chewer, too...

IMG_0813.jpg

[ClutchAutomatic]

Sorry to hear, my barrel should be back today. I will take it back out to the range this weekend with rounds of 123 eld-m and 8208 xbr loaded from 24-26.7.

[1075 tech]

FWIW, after reading this thread, I looked at the 16" GB barrel released around the same time as these 12.7's. The lugs on the extension look perfect, but it hasn't been installed yet. I'll have to look at the 18" I also received earlier but have yet to shoot.

[monty]

I must have gotten lucky with my barrel. I took it out again yesterday, and the minor scratching that it was causing before has gotten better with more rounds downrange. To the point that I am not going to bother trying to do any polishing. Seems to be polishing itself with use. The scratches are minor enough now that I don't think it will cause any problems.

[Truckd11]

ETA This was after 40 round of Hornady Black. Brass has some scratches and dents, brass is covered in soot.
Here are pictures of my bbl extension.